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<H1>merge_suspension_lists(+Pos1, +Attr1, +Pos2, +Attr2)</H1>
Destructively merge the suspension list on Pos1 in structure Attr1
into the suspension list on Pos2 in structure Attr2.


<DL>
<DT><EM>Pos1</EM></DT>
<DD>Integer indicating the position of the suspension list.
</DD>
<DT><EM>Attr1</EM></DT>
<DD>Compound term, typically a variable's attribute.
</DD>
<DT><EM>Pos2</EM></DT>
<DD>Integer indicating the position of the suspension list.
</DD>
<DT><EM>Attr2</EM></DT>
<DD>Compound term, typically a variable's attribute.
</DD>
</DL>
<H2>Description</H2>
   This predicate is used to merge two suspension lists. The list
   in Attr1 remains unaffected but the list in Attr2 is replaced
   by the merge of the two lists.

<P>
   Suspension lists should be regarded an opaque data structure and
   only be accessed and manipulated by the set of primitives provided
   for this purpose.

<P>

<H3>Modes and Determinism</H3><UL>
<LI>merge_suspension_lists(+, +, +, +) is det
</UL>
<H3>Exceptions</H3>
<DL>
<DT><EM>(4) instantiation fault </EM>
<DD>Pos1, Pos2, Attr1 or Attr2 is not instatiated.
<DT><EM>(5) type error </EM>
<DD>Pos1 or Pos2 is not an integer.
<DT><EM>(5) type error </EM>
<DD>Attr1 or Attr2 is not a structure or has no suspension list on the indicated argument position.
<DT><EM>(6) out of range </EM>
<DD>Attr1 or Attr2 does not have a Position'th argument.
</DL>
<H2>Examples</H2>
<PRE>



</PRE>
<H2>See Also</H2>
<A HREF="../../kernel/suspensions/insert_suspension-3.html">insert_suspension / 3</A>, <A HREF="../../kernel/suspensions/insert_suspension-4.html">insert_suspension / 4</A>, <A HREF="../../kernel/suspensions/schedule_suspensions-2.html">schedule_suspensions / 2</A>, <A HREF="../../kernel/suspensions/init_suspension_list-2.html">init_suspension_list / 2</A>, <A HREF="../../kernel/suspensions/enter_suspension_list-3.html">enter_suspension_list / 3</A>
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